build: W600-SDK importiert, Firmware-Build und Hello am EVK

Docker-Build mit gcc-arm-none-eabi 4.9-2014q4 (statt Homebrew-Cask) verwendet,
Dockerfile/tools/docker.sh dafür aus Task 13 vorgezogen. cmake/sdk.cmake schont
gcc 4.9 (kennt -fcommon/-Wno-error=... nicht). Zwei zusätzliche SDK-Stubs
(EarlyInit, pre_gpio_config) in src/sys/sdk_stubs.c ergänzt, siehe sdk/PATCHES.md.

sdk/Platform/Boot/gcc/retarget.c

@@ -0,0 +1,93 @@
+#if GCC_COMPILE
+#include <reent.h>
+
+extern int sendchar(int ch);
+
+_ssize_t _write_r (struct _reent *r, int file, const void *ptr, size_t len)
+{
+	size_t i;
+	char *p;
+	
+	p = (char*) ptr;
+	
+	for (i = 0; i < len; i++) 
+	{
+		sendchar(*p++);
+	}
+	return len;
+}
+
+_ssize_t _read_r(struct _reent *r, int file, void *ptr, size_t len)
+{
+	return 0;
+}
+
+int _close_r(struct _reent *r, int file)
+{
+	return 0;
+}
+
+_off_t _lseek_r(struct _reent *r, int file, _off_t ptr, int dir)
+{
+	return (_off_t)0;	/*  Always indicate we are at file beginning.  */
+}
+
+int _fstat_r(struct _reent *r, int file, struct stat *st)
+{
+	return 0;
+}
+
+int _isatty(int file)
+{
+	return 1;
+}
+
+void abort(void)
+{
+  while(1);
+}
+
+extern char end[];
+extern char __HeapLimit[];
+static char *heap_ptr = end;
+static char *heap_end = __HeapLimit;
+/**
+ * @brief          This function is used to extend current heap size, Limit is __HeapLimit
+ *
+ * @param[in]    None  
+ *
+ * @return         None
+ *
+ * @note           Normally, it is just used in gcc mode.
+ */
+void * _sbrk_r(struct _reent *_s_r, ptrdiff_t nbytes)
+{
+	char *base;
+
+	base = heap_ptr;
+
+	if(base + nbytes > heap_end)
+    {
+		return (void *)-1;
+    }
+
+	heap_ptr += nbytes;	
+	return base;
+}
+
+void * tls_reserve_mem_lock(int nbytes)
+{
+	if(heap_end - (nbytes + 4) <= heap_ptr)
+	{
+		return NULL;
+	}
+	heap_end  -= (nbytes + 4);
+	return (void *)((((int)heap_end + 3) >> 2) << 2);	
+}
+
+void tls_reserve_mem_unlock(void)
+{	
+	heap_end = __HeapLimit;
+}
+
+#endif